PREPOLYMERIZED ORGANIC-INORGANIC HYBRID NANOPARTICLES AS FILLERS FOR LIGHT-CURED METHACRYLATE MONOMERS.

V. MUCCI; G. ARENAS; C.J. PEREZ; C.VALLO

Praga

Conferencia; 7th International Conference on Nanostructured polymers and nanocomposites; 2012

Light-cured dental materials consist of free-radical polymerizable methacrylate monomers filled with a mixture of different inorganic fillers1. The polymerization of the methacrylate monomers is initiated by radical-forming photoinitiators, which decompose under irradiation with visible light in the region of 450-480 nm (blue light) 2. The inorganic fillers are incorporated to reduce the polymerization shrinkage3; which contributes to the development of contraction stresses that often lead to bond failure and recurrent caries4. According to a recent review by Ferracane 5, the most important changes in resin-based dental composites have involved the reinforcing filler, which has been purposely reduced in size to produce materials that are more easily and effectively polished. Due to the small particle size, i.e. large specific surface area, the interaction between the matrix and the surface of the particles is dramatically increased6. This raises the viscosity of the filled resins and reduces the attainable filler load. Thus, it is important to devise methodologies to introduce high amounts of inorganic fillers into resin composites. In this context, the preparation of silica nanoparticles in organic liquid media is especially interesting. The present study was carried out in order to explore the possibility of incorporating high amounts of inorganic filler into an organic monomer by the sol-gel process